Fighting the silent thief of sight

It’s World Glaucoma Week from 6-12 March 2016. As the UK’s main eye research charity, Fight for Sight is pushing the boundaries of glaucoma research.

Recent advances made on the world’s second leading cause of blindness with funding from Fight for Sight include

• discovering new biological pathways that may affect glaucoma risk

• identifying new targets for treatment

• developing an eye movement test that could help early diagnosis

Eye development, nerve degeneration and mitochondrial dysfunction: new risk factors for glaucoma

Dr Pirro Hysi at King’s College London is part of a team of researchers that has recently discovered 3 new genetic risk factors for the most common type of glaucoma. Variations in the genes TXNRD2, ATXN2 and FOXC1 are linked to primary open angle glaucoma, known as the ‘silent thief of sight’ because early symptoms go unnoticed.

This is the first time FOXC1 has been linked to a common adult glaucoma and the first time TXNRD2 and ATXN2 have been linked to glaucoma at all. The known functions of these genes open up new pathways for research, for example into the effect of failing energy production by the mitochondria – the ‘power plants’ inside cells.

Genetic epidemiologist Dr Hysi took part in the study with funds from a Fight for Sight Early Career Investigator Award. He said: “Our results suggest new pathways in eye development, neuro-degeneration and mitochondrial dysfunction that may contribute to the risk of developing glaucoma.” The research is published in Nature Genetics.

Strengthening the white of the eye to prevent damage from high eye pressure

Dr Craig Boote and his team at Cardiff University have discovered that the white of the eye (the sclera) remodels itself during glaucoma in a way that likely changes its mechanics and damages the optic nerve. High pressure in the eye (ocular hypertension) is one of the most common risk factors for glaucoma. It can squeeze the retinal ganglion cells that form the optic nerve, causing permanent sight loss.

The damage from high pressure is transmitted to the optic nerve via sclera. In his Fight for Sight project Dr Boote used high-power x-ray and microscope technology to study the connective tissue protein collagen in the sclera under high-pressure conditions.

The results, published in PLoS ONE, show that in glaucoma, collagen fibres rearrange. This opens up the possibility that collagen ‘cross-linking’ treatment to strengthen the sclera could be used to treat the people who don’t respond to pressure-lowering eye drops.

Developing a simple test to pick up undiagnosed glaucoma

Professor David Crabb and team at City University in London have found proof-of-principle evidence that eye movements can reveal glaucoma. Participants in their study watched ordinary TV and film clips on a computer as their eye movements were recorded with an eye-tracking device. The data were turned into a map of eye movements that the team could use to tell the difference between people diagnosed with glaucoma and people with healthy vision.

Although these are early results they point towards a future test that could catch glaucoma before sight loss begins. At the moment around half of people with glaucoma don’t yet know they have it.

Prof Crabb says: “We continue to work on a simple test for glaucoma using people’s eye movements whilst they watch TV. We hope the test could be widely used for finding undiagnosed glaucoma.” The results are published in Frontiers in Aging Neuroscience.

Dr Dolores M Conroy, Director of Research at Fight for Sight, said: “Getting a better understanding of the risk of glaucoma, developing new treatments, especially for those who don’t respond to eye drops, and diagnosing before sight loss are all high priority areas for people affected by glaucoma. We know this from the Sight Loss and Vision Priority Setting Partnership. I’m glad to see our strong glaucoma research programme making clear progress towards these goals. Our ongoing research projects are also investigating ways to protect the optic nerve from damage as well as regenerating it with stem cell based therapies.”

More Fight for Sight glaucoma research.

World Glaucoma Week is collaborative project between the World Glaucoma Association and the World Glaucoma Patient Association.